Microsoft did its best Woody Harrelson impression this week and set out to bag some zombies. The zombies we’re talking about here are PCs infected with malware. The bad guys spread the malware around and then remotely control victims’ computers as part of a botnet that can do stuff like send out spam email or carry out DDoS attacks.In the real world, of course, you have to aim for the head to kill zombies, and that’s basically the new strategy Microsoft used. In order to take down Waledac, which was one really bad botnet, it was granted a temporary restraining order from a federal judge that allowed it to cut off 277 Internet domains believed to be run by Waledac’s controllers. That severed traffic to Waledac at the “.com” or domain registry level — essentially decapitating it.Waledac’s main job was spam. It had hundreds of thousands of infected computers ready to do its dirty work, and it could send 1.5 billion pieces of junk email per day — fraudulent offers for counterfeit goods, BS jobs, worthless stock-pumping scams, questionable pharmaceuticals, all the usual stuff.Microsoft’s strategy seemed to work, but it may not be so easy to take down all botnets…